627
FXUS63 KMQT 121121
AFDMQT

Area Forecast Discussion
National Weather Service Marquette MI
721 AM EDT Wed Aug 12 2026

.KEY MESSAGES...

- There is a roughly 20% chance for showers and storms this
afternoon. Severe storms are not expected.

- Temperatures are expected to be seasonably warm to slightly above
average today, before cooling to slightly below average through the
weekend.

- Dry weather Thursday and Friday ahead of the next chances for more
widespread rain this weekend (around 60% chance).

&&

.DISCUSSION...
Issued at 246 AM EDT Wed Aug 12 2026

GOES-East Nighttime Microphysics RGB imagery shows a few tall
thunderstorms south of the state line, though one of the weaker
cells appears to be tracking towards the Menominee/Marinette metro.
While a few lightning strikes have been sparsely observed, the
impacts should be low as the storm continues to be weak among a
stabilized nighttime surface layer and absent of much synoptic
forcing or shearing mechanism. Also evident on the RGB is some
scattered midlevel cumulus and some patches of low stratus/fog that
are causing some vis restrictions at ESC, IWD, and CMX airports this
morning. While temperatures will continue to fall towards the dew
point (already matching it at some locations), the model signatures
for fog are mixed. Thus, maintaining the ongoing expectation of
patches to areas of fog, some dense, but not enough confidence to
issue an advisory (though if coverage increases around the commute
times, may issue an SPS).

RAP analysis aloft shows general northwesterly flow extending from
the Atlantic Seaboard to the lee of the Canadian Rockies. Ridging
extends across much of the southern tier of the US (highest 500mb
heights over the Gulf Coast but the northern extent of the ridge
axis is over the US Rockies). Meanwhile a closed low remains
over Hudson Bay and a trough is over the Pacific Northwest. The
latter trough will provide the best mechanism to progress the
weather pattern, though progress will have to wait for later in
the week as today looks to be yet another day of northwest flow
aloft leading to low confidence in diurnally-boosted
showers/thunderstorms. Ignoring the CAMs that do not have a good
handle on ongoing thunderstorms in Wisconsin, the most
aggressive CAM in convective initiation is the 00Z WRF ARW,
which shows weak thunderstorms forming at the confluence of lake
breeze boundaries at 18Z, with the remainder of the CAMs
showing weak and isolated showers in the proceeding hours.
Similar to yesterday, the UP lacks synoptic support for forcing
and has mostly unidirectional, weak shear (especially in the
lowest ~250mb where wind speeds only rarely exceed 20 kt).
SBCAPE is also similar to yesterday, with a HREF mean of up to
500 J/kg, but the spread from minimum to maximum in the ensemble
is 1000+ J/kg.

Thursday and Friday, the kicking trough will first kick ridging from
over the Rockies and Plains to be over the Midwest and Great Lakes.
This will lead to rising surface pressure and mostly dry conditions
for virtually all of the UP Thursday and Friday, though temperatures
in the 70s look to be around seasonal to even cooler-than-normal.
The exception to the dry conditions Thursday would be the scenario
presented by a few of the CAMs where the messy remnants of MCS
structures in Minnesota move over the UP, though even if this
does occur (less than 50% chance) impacts will be low as these
are unlikely to have enough support or buoyancy to sustain as
thunderstorms and even the 90th percentile of HREF 24hr QPF is a
tenth to a quarter inch for a reasonable wettest case scenario.

The aforementioned kicking trough arrives over the UP Saturday.
Unfortunately and unsurprisingly, spread in the track and depth of
this trough passage remains high. At the same time as the trough
arrives, ridging builds over the Southeast, allowing for ensembles
to have a spread of solutions regarding how this trough fares
against either a weaker or stronger Southeast ridge. Current LREF
chances of a wetting rain (around a tenth of an inch/24hr) is around
50-65% by Sunday morning. Thunderstorms are uncertain as well,
though the LREF mean SBCAPE by 00Z Sunday being 100 or less J/kg is
not an encouraging sign for those looking forward to a rumble of
thunder. While there is understandable spread on the pattern that
follows, it is generally expected that by Sunday evening and through
Monday night, ridging resumes in the wake of the trough. Next
Tuesday looking to resume the ongoing pattern of weak precip signals
in persistent NWerly flow, unless the ensembles can coalesce around
the global deterministic models which each have their own idea of
how the closed low aloft over Hudson Bay may gyrate south enough
into northern Ontario to bring decent enough PVA to support showers
and storms.

&&

.AVIATION /12Z TAFS THROUGH 12Z THURSDAY/...
Issued at 721 AM EDT Wed Aug 12 2026

VFR conditions prevail at all sites this morning. Similar to
yesterday, 15-30% chances of SHRA/TSRA are expected especially at
the confluence of the Lakes Michigan and Superior lake breezes,
which means SAW may see those conditions but CMX will be too far
north and IWD will be too far west. A PROB30 will cover that
precipitation chances this afternoon. Otherwise, chances of FG
development overnight tonight are around 15%, so have left mentions
of FG out of all TAFs. Another PROB30 for SHRA is noted at SAW late
in the TAF as some models indicate that remnant precip from
thunderstorm complexes in Minnesota may survive and reach the UP,
with SAW most likely to see it around 12Z at around 30%, but it is
plausible that CMX/IWD could also see some precip if the track of
those showers shifts.

&&

.MARINE...
Issued at 246 AM EDT Wed Aug 12 2026

Mostly calm weather with winds 15 kts or less will be seen over the
area the next few days, save for potentially some showers and
thunderstorms over northern Green Bay and Lake Michigan through this
evening (no severe weather expected). However, as high pressure
begins to move out of the Upper Great Lakes on Friday, we may see
some northeasterly winds of 20 to 25 knots over the far western lake
near the Apostles and Duluth by Friday afternoon as low pressure
approaches from the west. While winds weaken by Friday night, they
restrengthen once again by Saturday as a shortwave low brings what
appears to be an occluding front over the Upper Great Lakes. Thus,
expect southeast to southerly winds up to 20 kts over central Lake
Superior, in addition to the showers and storms moving across the
area. Behind the front into Sunday, expect the winds to weaken,
although they may increase up to 20 to 25 knots from the northwest
over Lake Superior again by Sunday afternoon.

&&

.MQT WATCHES/WARNINGS/ADVISORIES...
Upper Michigan...
None.
Lake Superior...
None.
Lake Michigan...
None.

&&

$$

DISCUSSION...GS
AVIATION...GS
MARINE...GS